Electrical control system for refrigeration



Oct. 27, 1931 F.- e. KEYES 1,829,403

7 ELECTRICAL CONTROL SYSTEM FOR REFRIGERATION Filed Nov. 10, 1923 2SheetS Sheet l nsrmcsmvrms CHAHBER- INVEINTOR W fi HIS ATTORNEY F. G.KEYES Get. 27, 1931.

ELECTRICAL CONTROL SYSTEM FOR REFRIGERATION Filed Nov. 10, 1923 2Sheets-Shee ATTORNEY Patented Oct. 27, 193 1 UNITED STATES PATENT OFFICEFREDERICK G. REYES, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR, IBY MESNEASSIGN- MENTS, TO FRIGIDAIRE CORPORATION, A CORPORATION OF DELAWAREELECTRICAL CONTROL SYSTEM FOR REFRIGERATION Application filed November10, 1923. Serial No. 673,931.

My present invention relates to electrical control systems and toswitches of the flowing mercury type useful therein and particularly toa time switch of this'type. It-further relates to a multiple pole switchof this type. Herein my switches are shown and described in connectionwith a new and novel electrical control system as applied to'arefrigeration system, but the switching system is applicable in the artsgenerally.

Switches of the mercury flow type, which are desired in the presentinstance, generally comprise a sealed glass envelope having a quantityof mercury therein and electrode terminals sealed therethrough and thegeneral mode of operation is to tip or tilt the envelope to cause themercury therein to flow-to or from the electrodes to affect the closingor opening of electric currents therethrough.

Such switches have for certain conditions a filling of gas such ashydrogen or nitrogen.

The object of my-invention is to provide an electrical control systemand apparatus. 7

Another object of my invention is to provide a mercury switch foralternating the energization of two sets of electrical translatingdevices. 7 7

Another object of my invention is to' provide a mercury switch in whichthe mercu takes a definite time to flow after the switc is tipped beforesufficient mercury'gathers to connect the electrode terminals throughwhich it is desired to have current pass or to disconnect suchelectrodes.

In the accompanying drawings which form part of this application I haveshown an embodiment of my invention which comprises two chambers havingelectrodes therein, said chambers being connected at the bottom by a 0capillary or flow restricting tube having therein another electrode, andsaid chambers being connected near their top by a tube for equalizingthe pressure of the gases or mercury vapor in the two chambers. When the5 switch is tipped in the direction of one of the chambers and themercury has flowed thereto an electricalconne'ction will be establishedbetween the electrode or electrodes of said chamber and the electrode ofthe flow restricting 0 tube. The electrical connection through the .alsoshown in the drawings an application of will remain established untilthe mercury flows away from the electrode thereof and the time of thisflow is predetermined. I have this switch of my invention to arefrigeration system and have described herein its function andoperation as a part of such system.

In the drawings Fig. 1 is an elevation view of an embodiment of myswitch which is tipped to secure the flow of mercury to one chamber andthe establishment of an electrically conducting path therethrough.

Fig. 2 is an elevation view similar to Fig. 1 but showing the switchtipped for the establishing of a circuit through the other side thereofand showing the mercury therein as having flowed to said other side.

Fig. 3 is a vertical elevation of a switch embodying my invention inwhich there is suflicient mercury to connect the three electrodesthereof when the switch is in the vertical position.

Fig. 4 is a view similar to Fig. 3 showing a switch which is completelyopen when left to stand in the vertical position.

Fig. 5 is an elevation view showing the switch of my invention in atipped position but in which the mercury has not yet flowed suflicientlyto disrupt the connection through the higher side and establish theconnection in the lower side.

Fig. 6 is a diagrammatic representation of a refrigeration systemshowing my switch in the electrical control system thereof.

Fig. 7 is an end view of the switch tilting mechanism.

Fig. 8 is a front elevation of Fig. 7.

Referring to Fig 1, switch 49 is provided 90 with two electrodes, 80and. 81, mounted in tubular chambers 82 and 83 and which have connectedto them the lead in wires, 87 and 88, respectively, which are sealedthrough the walls of their respective chambers The capillary or flowrestriction tube, 85, connects the chambers 82 and 83 near their hottomsand has sealed into it the terminal elec trode 86.

break is made .In one form of my switch suflicient mercury is sealed inthe tube to electrically 'connect all three electrodes 80,81 and 86 whenthe switch is in the upright position as shown in Fig. 3, but thequantity is provided such that when the switch is tipped to one side-orthe other the mercury flows from one of the chamber electrodes todisrupt the electrical connection on that side, the mercury assuming aposition similar to that shown in Fig. 1 or 2. The restriction on theflow of the mercury by the tube 85 provides that such disruption doesnot occur until a definite time after the tipping of the switch, suchtime being predetermined by the design of the switch involving suchelements as the size of the tube 85,1he amount of mercury in the switch,the positions of the electrodes andso on.

In another form of my -switch as shown in Fig. 4 connection is disruptedthroughout the switch when the mercury in the two chambers is about thesame in quantity. Such a condition would exist when the switch is leftto stand at or near the vertical position sufficiently long for themercury tocome to or near gravimetric' equilibrium. Such also is the.condition of the switch at one stage in the flow of the mercury aftereach tilt from one side to the other. In the form shown in Fig. 3 asimilar condition would exist but in that case electrical connect-ionswould be established throughout the switch at such positlons.

In my switch the tube 116 connecting the electrode terminal chambers 82and 83 near their tops serves to allow an equalization to take placebetween the gases or vapors in said chambers.

The first of these forms above mentioned can be used without using theelectrode 86 or the switch may be made'without this electrode, In suchcase the mercury is used to make and break connection between. theelectrodes and 81, the tube serving to regulate-the interval at whichthemake or after the movement of the switch.

Or my switch with theelectrode 86 can be used for making and breaking acomplication of circuits such for instance as is shown in my copendingapplication, Serial No. 359,882, filed Feb. 19, 1920, patented March 29,1927,

No. 1,622,519, of which this application is,

in part, a continuation.

In Fig. 6 of the drawings is shown my switch in the electrical controlsystem of a refrigeration apparatus. In this figure is shown a still ordistillation chamber, 13, in which is situated a suitable electricalheating coil (not shown) connected through wires 1 and 2 to electricsupply mains 11 and 12, respectively. Between lead 2 and main 12 areconnected suitable control mechanisms hereinafter further described. Acondensing chamber 16 is connected to the still 13 by the pipe 17,manifold 18, check valve 19 and pipe 20. Y

The check valve allows refrigerant vapor of the system to pass throughit' from still 13 to condenser 16 but prevents flow through densingchamber 16 is a cooling system of water supply and distribution pipes, acooling coil for the condensing chamber and one for 1 the still chamber(both shown in dotted lines), and an electrically controlled two-wayvalve 29 which latter serves to direct the flow of the water alternatelythrough the cooling coils of said still 13 and chamber 16. The pipe 30connects the cooling system to the water supply mains through said twoway valve 29. The pipe 31 connects the main 30 through one position ofvalve 29 to the cooling coil (not shown) of still 13 which dischargesthrough pipe'39 to discharge pipe 35. The main 30 is connected throughvalve 29 at its other position through pipe 32 to the cooling coil (notshown) of still 16, thence through pipe 34 to discharge pipe 35..

The valve 29 is operated to direct the flow of water either through pipe31 or pipe 32 by means of a doublearmature 42, one end of which works insolenoid 40 and the other end in solenoid 41. By means of an automaticsystem of electric switches hereinafter described the solenoids arealternately energized to cause the plunger 42 to move to actuate valve29 to alternately direct water through the cooling coils of the stilland the ,condenser.

The periodic flow of current through heating coil of the still and theflow of water through valve 29 alternately to the cooling coil condenser16 and to cooling coil of the still 13 are controlled by means of anelectrical system including switches 48, 49, 50 and 51 and a switchingarrangement in refrigerating chamber 25. I The switches 48, 49, 50 and51 are mounted on a rocking beam 67 (see Figs. 7 and 8) which iscontrolled and actuated by the armatures 54 and 55 which work insolenoids 52 and 53 respectively as fully set forth in my priorapplication filed February 19, 1920, Serial No. 359,882. Switch 48 makesand breaks a connection in the circuit of solenoid 40, one side of whichis connected through wire 5 to one side of said switch 48 and the otherside through wire 4 to the main 11. The other side of switch 48 till isconnected both to one side 49a of time switch 49 and to one side ofsolenoid 52, the other side of said solenoid 52 being connected to thewire 56 and through it to contact 57 in said refrigerator chamber 25.Mounted on float 62 within said chamber 25 is a contact making disc 58which, when float 62 is at its upper limit of movement, makes contactwith said contact 57 and a corresponding contact 59 which latter withwires 60 and 61 make connections with main 11. The midpoint 490 ofswitch 49 is connected to main 12 through wire 8. The side 49?; ofswitch 49 is connected through wire 10 both to switch 50 and solenoid53. The other side of switch 50 is connected through wire 9 and solenoid41, through wire 4 to the main 11. The other side of solenoid 53 isconnected through wire 63, contact 6 1, contacting disc 58, contact 65,wire 66, wire 61 to main 11. The switch 51 is connected on ,one sidetomain 12 and on the other to the heating coil 15 and thence to main 11.

The operation of the refrigerating system of my invention as describedabove is as follows, starting with the switching apparatus in theposition shown in Fig. 6, with the electric mains 11 and 12 connected toa source of current and with no refrigerant in the refrigerating chamber25. The refrigerant will be in the still 13 physically or chemicallycombined with the absorbent material, and the heating coilthereof willbe energized. When sufiicient heat has been generated in the still thevaporized fluid will be forced by the resulting'pressure through pipes1? and 20 into the condenser chamber 16. Valve 29 being open on thecondenser side, the water flowing through the cooling coil thereof willcool the fluid in chamber 16, causing it to condense. .Vhen a sufficientquantity of liquid has collected in chamber 1 a valve therein (notshown) will be float operated to Open thereby allowing' the liquid toflow through pipe 2% into the refrigerator chamber 25, where collects.This collection and discharge occurs repeatedly and as the level of theliquid in chamber 25 ris s it carries float 62 upward and lifts com 58up to contacts 5? 5 trical connecticntherebet 3 Current will throughconductor 6" contactor 53, cor solenoid 52, conducto 3 to main 12,thereby the armature 54 o ':i pullthe switch v tches 50 and 51 win theirtingoff the heating on e coil fiwitch w l i itch will be established formain 11, wire 4, solenoid 40, wire 5, switch 48, wire 7, the 49a side ofswitch 49, terminal 490, wire 8,'to main 12, whereupon solenoid 40 willbe energized and valve 29 actuated to close the port to cooling coils 33and to open the port to pipes 31 and 37 and to cooling coils 36 and 38whereby still 13 is cooled. The current .passing through solenoid 40 forfive seconds insures the moving of the valve 29 to its proper position.The cooling of the still 13 results in a considerable decrease inpressure therein and in refrigerating chamber 25. lVith the decrease inpressure there is a rapid vaporization of the liquid in refrigeratingchamber 25 and a consequent decrease in temperature. The vaporizationand decrease in temperature in chamber 25 continue until contact is madeby contactor 58 between contacts 64 and 65, switch 51 is closed andpressure raised in still 13.

As the liquid in chamber 25 vaporizes its level therein falls and withit the float 62 until the contactor 58 strikes'contacts 64: and 65whereby the circuit is closed from conductor 11, through conductors 61and 66, contact 65, contactor 58, contact 64, conductor- 63, solenoid53, switch l9 (side 49b), conductor 8, to main 12. The solenoid 53 nowbeing energized and solenoid 52 tie-energized, switch 18 will be opened,switches 50 and 51 will be closed, and switch e297) will remain closedfor a period of five seconds during which solenoidl1 will he energizedfor the actuation of valve 29 to close the port to pipes 31 and 3'? andto the cooling coils of still 13 and to open the port through pipe 32 tothe cooling coil of the condenser 16 whereby chamber 16 is cooled.Heating current now flows through heating coil 15 in still 13 andcooling water flows through the condenser coils, the water throughstill. coils being turned off.

i igain the vaporizeo refrigerant will pass from the still 13 to theconden 16 where it switch it can be seen that my invention is capable ofapplicationin a number of ways and with various kinds of machinery,apparatusfletc. I claim: I

1. In an electrical control system, the combination of two switches foropening and closing electrical circuits therethrough, means for movingsaid switches to simultaneously close a circuit through one switch andopen another circuit through another switch, and liquid level controlledmeans for closing and opening alternately the circuit of said firstnamed means.

2. In an electrical control system, the combination of two switches foropening and closing electrical. circuits therethrough, means for movingsaid switches to simultaneously close. a circuit through. one switch andopen another circuit through another switch, liquid level controlledmeans for closing and opening alternately-the circuit of said firstnamed means, and means for opening the circuit to a closed switch aftera time interval.

3. line refrigeration apparatus having a generator connected to acondensing chamber, reirigerationchamber having upper and lower sets ofelectric contacts mounted thereon and connected to said generator and tosaid condenser chamber, heating means for said generator, and means forcirculating cooling water to said generator and to said condenserchamber both fed from the same source through an electrically operatedtwo-way valve, combination, a three electrode mercury switch having oneelectrode tively common to the other two, and

incrci J swit hes having electrodes in each end thereof, and means inthe first named to retard the i'iow of mercury therein mercury in oneelectrode uniting or a deli..."

the switch has been moved into the other refrigeration chamber carryinga contactor which establishes electrical circuit through r set ofelectric contacts and said the'upper limit of movement of i todeenergize said heater and to c said electrically operated two-way toturn. water from said generator means and to turn water to saidconchamber cooling means and at the it of: such movement through the Wof contacts and said switches to ice said heater and to actuate saidelec- -perated two-wa r valve to turn coold generator cooling means tocondenser chamber to "crating apparatus, in como. connected through ainto a condensing chamber,

period of time after fisher, connection between aeacgcos the condensingchamber and the refrigerat ing chamber, a one-way conduit from the refrigerating chamber into the generator, a cooling coil for thegenerator, a cooling coil for the condensing chamber, a two-way valveconnected from a source of supply for alternative distribution to saidcoils, an electro-magnet magnetically connected to said valve to open itto the generator coil and close it to the condensing chamber coil,

a second electrode-magnet magnetically connected to said valve to openit to said condensing chamber coil and close it to said generator coil,mercury-switch electrodes in the respective circuits of said magnets andI the condensing chamber and the refrigeratig chamber, a one-wayconduit'from the refrigerating chamber into the generator, a coolingcoil for the generator, a cooling coil for the condensing chamber, atwo-way valve connected from a source of supply ior alternativedistribution to said coils, an electro-mag'net magnetically connected tosaidvalveto open it to the generator coil and close it to the condensingchamber coil, a second electro-magnet magnetically connected to saidvalve to open it to said con densing chamber coil and close it to saidgenorator coil, mercury-switch electrodes in the respective circuits ofsaid magnets and positively mounted with respect to each other and thecontacting mercury to close the circuit upon the opening of the circuitof the other of said electro-magnets, and a time switch connected inseries with each of said magnet circuits with means therein for openingthe circuits thereof at a predetermined time after the establishing of acircuit therethrough and a liquid level control contactor and upper andlower setsof consignature.

FREDERICK Gr, KEYES,

